1. Technical Field
The present disclosure relates to integrated optics, and particularly to an electro-optic modulator.
2. Description of Related Art
Electro-optic modulators, such as Mach-Zehner electro-optic modulators, change a refractive index of a branch of a Y-shaped waveguide (hereinafter, the first branch) using a modulating electric field, utilizing an electro-optic effect. Thus, the modulators can alter a phase of lightwaves traversing the first branch. As a result, the lightwaves traversing the first branch can be phase shifted, and thus interfere with lightwaves traversing another branch of the Y-shaped waveguide (hereinafter the second branch). An output of the Y-shaped waveguide is modulated as the output depends on the phase shift, which in turn depends on the modulating electric field. Since only one of the branches is modulated, a required modulating voltage is relatively large, and with low modulating efficiency.
Therefore, it is desirable to provide an electro-optic modulator that can overcome the above-mentioned problems.